During the April 27, 2021 Planning Subcommittee (PSC) meeting, MISO reviewed draft language changes for Storage as Transmission-Only Asset (PAC004). MISO is requesting Stakeholder feedback on the following:
Please provide feedback by May 21.
Transmission Owner Sector Feedback on for Storage as Transmission-Only Asset (SATOA) BPM Language
May 21, 2021
During the April 27, 2021 Planning Subcommittee (PSC) meeting, MISO reviewed draft language changes for Storage as Transmission-Only Asset (PAC004) and requested Stakeholder feedback on the:
The Transmission Owners (Owners or TOs) submit the following feedback on the proposed Business Practices Manual (BPM) 020 Transmission Planning revisions only. Substantive comments are included in this feedback and editorial comments on the BPM language are being provided to MISO via email in the redlined version of the Word document posted with the Planning Subcommittee meeting materials.
The introductory statement in proposed BPM-020 Appendix A appears to be a definition of SATOA, but is not labeled as such, but should be. Regarding the definition of a SATOA in the BPM, the Owners think that it would be preferable to broaden the definition to eliminate the reference to Appendix A of the MTEP. Although inclusion in Appendix A of MTEP is necessary for a SATOA to be “approved” the definition should describe SATOAs more generally relative to the purpose of the BPM language, which largely addresses the submission and evaluation process in MTEP generally (see suggested redlined edits).
Appendix A Section A.2:
This section specifies that a SATOA approved in a prior MTEP cycle will be assumed to be available for operation in the current MTEP cycle to address the Transmission Issues the SATOA was approved for, which the Owners support, but additional consideration should be given to whether the SATOA may also be available to resolve a subsequently identified issue.
Appendix A Section A.3:
The proposed language in Section 2.3 notes that a SATOA may qualify as any project type, which the Owners support, but consideration should also be given to whether the same evaluation process should be applied to all storage solutions, regardless of whether they are submitted by the Transmission Owner or as an alternative Transmission solution.
Appendix A Section A.3.4
The last sentence of this section goes beyond what is required by MISO’s tariff and captures a requirement that is stated earlier in this section, where it is noted that the cost of additional upgrades necessitated by the SATOA to maintain reliability will be added to the SATOA project for purposes of project cost comparison.
The Environmental Sector appreciates the opportunity to comment on SATOA BPM 20 edits. We have a number of concerns and questions, in particular related to Generator Interconnection.
Application of SATOAs:
Appendix A “Planning for Electric Storage Facilities” notes:
“An electric storage facility may qualify as a SATOA if it meets the MISO Tariff criteria for a SATOA.[1] A storage facility will not be evaluated as a potential SATOA to resolve a routine (i.e., N-0 or N-1) Transmission Issue that can be addressed by a market solution.”
Our question is whether a storage facility will be evaluated as a potential SATOA to resolve a N-2 Transmission Issue that can be solved by a market solution? The market dispatch model can solve to N-1 with a line already out of service, effectively creating a N-2 scenario. Will storage be evaluated as a potential SATOA in this case?
Will BPM 15 Similarly be Updated to Include the Same Proposed Language?
Appendix A.2 to BPM 20 notes:
“A SATOA approved in prior MTEP cycles will be assumed to be available for operation in the current MTEP cycle to address the Transmission Issue(s) the SATOA was approved for when the SATOA was included in MTEP.”
Is this device similarly available for use as a solution in the same manner in DPP studies, and if so, does MISO plan to make a similar addition to BPM 15? If so, these changes should be made at the same time.
Inverter-Based Reliability Requirements and Analysis:
Section A.3.2.1 requirement does not cover all inverter-based requirements of storage connecting as a generator in BPM 15
In the SATOA Tariff filing and the meetings leading up to it, MISO clearly explained that SATOAs would be subject to the same requirements as all inverter devices in the GIP. NERC PRC-024 is not the only requirement for inverter-based resources in the GIP. Please explain the justification for the difference (or apparent difference) in treatment.
Language in Section A.3.4 Does not Mitigate Potential Harm to Generators Posed by SATOAs:
We strongly recommend that MISO make revisions to the proposed Section A3.4 of BPM 20 to better mitigate any potential harm to generators. Generators in the queue or with signed GIAs but not included in the MTEP model must be added to the MTEP model and dispatched at 100% output for any reasonable “impact analysis” of SATOAs. As currently proposed, nearby generators “may be included” and this is insufficient. Additionally, generators in the queue that are electrically close to a proposed SATOA MUST BE NOTIFIED of this proposed SATOA. These generators are being studied under older MTEP models but will face operational differences between their MTEP models/studies and the updates to the systems after they reach GIA. It is critical that a requirement to notify those generators be put in BPM 20.
Please Clarify that the Operating Guide for SATOAs will be Publicly Available:
Section A.4 of BPM 20 Appendix A notes the requirement for an “Operating Guide” to accompany the SATOA. In its Order on SATOAs, FERC noted that this Operating Guide should be made publicly available. Please either explain why it is not proposed to be made publicly available or update this language accordingly.
Useful Life of a SATOA:
We appreciate MISO’s inclusion of Appendix A Section A5 which offers clarification on retirement of SATOAs. SATOAs are planned for a 20 year life, but in reality, may be retired earlier, particularly when costly upgrades are needed around 10 years. We request that similar to our request for additions of SATOAs, all projects in the MISO generator interconnection DPP process electrically close to the proposed retired SATOA be notified of the request for retirement. In both cases, the interconnection customers should be notified prior to the SPM where the inclusion or retirement will first be presented to stakeholders. This will allow for questions to be asked and any concerns to be raised.
[1] See MISOTariff, Attachment FF, Section II.G.
DTE appreciates the feedback opportunity to contribute to this topic. Here are a couple of points:
Concerning Section 3.3 of Appendix A, AES Indiana believes that more details are needed on the selection criteria when benchmarking against the other types of solutions. MISO’s current proposal states that the SATOA must have certain characteristics but fails to elaborate on what those characteristics are.
Additionally, regarding Section 4.4 of Appendix A, AES Indiana stresses that operation of the asset in real-time needs to preserve flexibility with respect to the SATOA owner’s commercial and reliability objectives.
Savion, LLC (“Savion”) would like to thank MISO for bringing this item to stakeholders for discussion. As noted in prior discussions with MISO on this topic we believe a fundamental issue MISO has with SATOA and the inclusion of DPP generation in the evaluation is the fact that if MISO adds the queued DPP storage resources to the models there is a good chance that such generation resolves the issue and makes the SATOA unnecessary.
1) SATOAs are supposed to mitigate any potential impacts to projects in the MISO DPP, but MISO plans to employ MTEP models, not DPP models, to check for impacts. Thus, the power flows (and constraints) on lines are greatly reduced. Per MISO’s current proposal, DPP projects in the vicinity of the SATOA will be added to the MTEP model and dispatched at 100% output to check for impacts. We do not believe this is a sufficient proposal for identifying harm to GI requests in the DPP. It is prudent that MISO also includes SATOA projects within the DPP study models to identify potential impacts that may occur within the MISO LGIP.
2) Referring to A.3.4 of the proposed BPM-020 language, DPP projects that have executed GIAs but are not included in MTEP models need to be included in impact studies as well as all DPP projects electrically close. MISO proposes that it "may" add nearby generators in the DPP to check for harm. This "may" should be changed to "shall". Further the phrase “significant negative impacts” is vague. The word “significant” should be eliminated and the remaining words “negative impact” should be clearly defined.
3) MISO needs to notify DPP projects that are electrically close to the SATOA and do so before the SPM (Sub-Regional Planning Meeting) when the SATOA is first introduced. This is critical. The last time a SATOA was approved, MISO did not add most of the nearby queued projects to the study model, dispatched what few were added at low levels so no harm could be attributed to the SATOA and didn't inform ANY of the nearby generators in the DPP of the "harm" study. (MISO also only performed a MTEP power flow study, but did not perform voltage stability, harmonics, short circuit, transient analysis, affected systems, etc.).
4) SATOAs are only to be considered for N-2 situations and are required under MISO's Tariff to have operating guides. Operating guides are not currently publicly available, meaning you cannot know about them in your DPP models, but they impact overloads and contingencies in N-2 scenarios. FERC recommended MISO make the SATOAs operating guides publicly available and this should be included in the BPM.
5) SATOA modeling details in MTEP are being proposed for addition to BPM 20. Similar details should be added to BPM 15.